Total ankle replacement surgery, or total ankle arthroplasty, is an evolving area in orthopedic surgery. Recent advances in prosthetic devices and instruments for placement of the prostheses in the bone have made this a relatively common procedure. During the evolution of this procedure new problems are becoming apparent with existing systems, and there is a need to address some of these to improve the outcome of this type of surgery for patients.
One type of total ankle replacement has a tibial prosthetic component that has an intramedullary or tibial prosthetic stem component. This stem is constructed from smaller modular tibial stem component pieces that are assembled within the tibial-talar space. As each new piece is added to the existing stem, the entire construct is driven further into the intramedullary canal of the tibia. During the surgical procedure the surgeon will determine how many of the component pieces need to be combined to form the optimum construct for that patient.
A problem that needs to be addressed is the capability of removing an implanted tibial prosthetic stem component. Most commonly this would be required in the event of infection of the prosthesis. There is really no way to eradicate infection without removing the prosthesis. It is important to do this in a matter that is not destructive to the remaining bone for ensuring the possibility that a new prosthesis could be implanted after the infection had been adequately treated.
With existing techniques and instruments the prosthesis with an intramedullary or tibial prosthetic stem component is difficult to remove without significantly damaging the tibia bone. The outer surface of the tibial stem component pieces are covered with a material that the surrounding bone grows into. Separating the bone from the stem pieces without removing excessive bone, and thus making further surgical reconstruction impossible, is difficult.
For example, one existing technique for the removal of the tibial implant is the requirement for large bone windows to be cut into the lower end of the tibia to remove the stem component pieces of the tibial prosthetic stem component that have become fixed into the bone during the initial surgical procedures. The result of this bone destruction yields a tibia that makes further reconstructive procedures particularly problematic.
Accordingly, there is a particular need to overcome the significant shortcomings in the removal of the intramedullary or tibial prosthetic stem component pieces of the tibial implant from the distal tibia during revision surgical procedures.